BQ25619E: BQ25619E REGN PIN output voltage out of spec & whether it can be replaced by peripherals power supply? BQ25619E REGN脚电压超规，是否可以使用外部电源替代来检测NTC？

Yong Wang

Part Number: BQ25619E
Other Parts Discussed in Thread: BQ25619,

We used the BQ25619E chip in our product for Li-on battery charging power management with the BQ25619 internal NTC temperature controlling, NTC pull up to REGN power.

We also measurement the NTC by MCU ADC port for software parallel protection.

But after measurement, we found the REGN voltage not same as specification claim. When USB Vbus is 5.5V as USB2.0 protocol up limitation, the REGN is 5.4V. When USB Vbus is 5.0V, the REGN is 4.9V rather than 4.8V. the REGN has too much fluctuation and caused software parallel big error.

So we wondering know, whether we can use a fixable 3.3V power rather than REGN power, for BQ25619E chip NTC detection.

Thanks for answer.

我们在产品中使用了BQ25619E芯片用于锂电池充电电源管理并且也使用了BQ25619内置的NTC温度控制，NTC端按照规格书推荐拉高到REGN电源。
我们还通过MCU ADC端口测量NTC，以实现软件并行保护。
但经过测量，我们发现REGN电压与规格宣传不符。当USB Vbus为5.5V作为USB2.0协议上限时，REGN为5.4V。当USB Vbus为5.0V时，REGN为4.9V而不是4.8V。REGN波动过大，导致软件并行误差较大。
所以我们想知道，我们是否可以使用可固定的3.3V电源，而不是REGN脚电压，来进行BQ25619E芯片NTC检测。
谢谢你的回答。

3 个月前

0 Taylor 3 个月前

TI__Mastermind 35385 points

您好，

已经收到了您的案例，调查需要些时间，感谢您的耐心等待。

0 Links 3 个月前

TI__Mastermind 31840 points

Hello,

Please make sure REGN is being tested as in the specifications table, with the load applied as specified. However, please note that the TS thresholds are based as a percentage of REGN rather than a fixed value. The NTC detection will work no matter what REGN goes to because it is referenced to it. Please make sure the probe you are using is high impedance so as not to affect REGN value.

0 Yong Wang 3 个月前回复 Links

Prodigy 10 points

If I use another fix power supply such as 3.3V to instead REGN power, is it OK for BQ25619 NTC detection?

0 Yong Wang 3 个月前回复 Links

Prodigy 10 points

If I use another fix power supply such as 3.3V to instead REGN power, is it OK for BQ25619 NTC detection?

0 Links 3 个月前回复 Yong Wang

TI__Mastermind 31840 points

Hello,

No, it has to be referenced from REGN. Applying 3.3V to REGN would create a sinking current from REGN to 3.3V. Do no overdrive TS nor REGN.

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BQ25619E: BQ25619E REGN PIN output voltage out of spec & whether it can be replaced by peripherals power supply? BQ25619E REGN脚电压超规，是否可以使用外部电源替代来检测NTC？